The present invention relates to a horn-holder pivot type bonding apparatus wherein the imaginary pivot point of the horn holder during bonding operation can be positionally fixed on a bonding surface.
Japanese Patent Application Unexamined Publication Disclosure Nos. 2003-347349 and 2005-236104, for example, disclose horn-holder pivot type bonding apparatuses. In these bonding apparatuses, it is designed so that the bonding head can be set at a higher position than the work plane, so that, even when the bonding area is large and broad, long-size ultrasonic horn and/or horn holder is not required. Accordingly, in the bonding apparatuses disclosed in the above-identified relevant art, it is possible to suppress the increases in the inertia of the ultrasonic horn and horn holder and to make the high speed operation of the bonding apparatuses possible.
More specifically, the bonding apparatus disclosed in Japanese Patent Application Unexamined Publication Disclosure No. 2003-347349 includes an ultrasonic horn having a capillary attached to a tip end thereof, a horn holder holding this ultrasonic horn, a drive motor provided at the rear end portion of the horn holder for driving the horn holder, and a bonding head that has a circular arc shaped window structure for supporting portions provided on both sides of the horn holder. The center of the circular arc shape of the circular arc window is set on a plane of the bonding surface, and the supporting portions of the horn holder are moved in a circular arc shape along the circular arc window of the bonding head.
In the apparatus of Japanese Patent Application Unexamined Publication Disclosure No. 2005-236104, circular arc shaped rotary shafts of rotary motors that rotate about the center of rotation of the horn holder are respectively secured on both sides of the horn holder, and rotary shafts of circular arc shaped bearings that rotate about the above-described center of rotation are provided so as to rotate on the outside of the rotary motors integrally with the rotary shafts of the rotary motors.
In the bonding apparatus of Japanese Patent Application Unexamined Publication Disclosure No. 2003-347349, the lengths of the ultrasonic horn and horn holder can be made shorter, so that the moment of inertia of rotationally movable portions including the drive motor, the ultrasonic horn and horn holder is small. However, in this structure, the drive motor is provided at the rear end portion of the horn holder that is distant from the center of rotation of the horn holder; accordingly, there is a limitation to the reduction of the moment of inertia.
In the bonding apparatus described in Japanese Patent Application Unexamined Publication Disclosure No. 2005-236104, the rotary motors are provided on both sides of the horn holder, and thus the moment of inertia is reduced even further. However, since the rotary shafts of the rotary motors are provided on both sides of the horn holder, and bearings are provided on the outer side of such motors, the size increase in the bonding apparatus is inevitable.
Furthermore, in both of Japanese Patent Application Unexamined Publication Disclosure Nos. 2003-347349 and 2005-236104, no consideration is given to the rigidity against the acceleration of the rotationally movable portions in an X axis direction which is a horizontal direction horizontally at right angles with respect to the axial direction of the horn holder (the X axis direction thus being perpendicular to the surface of the drawing sheet).